GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"32501 results found.
- GRB 240415B: GECAM-B detection
- EP 240416a: Xinglong and NOT decaying optical counterpart
- GRB 240415A: Swift-BAT refined analysis
- EP240416A: MASTER optical observations
- GRB 240411A: Glowbug gamma-ray detection
- GRB 240414A: Swift-BAT refined analysis
- EP240416a: Kinder optical counterpart candidate
- GRB 240414A: AbAO optical upprer limit
- GRB 240415A: Swift/UVOT Detection
- EP240413a: BOOTES-2/TELMA Optical Upper Limit
- GRB 240415A: Fermi GBM Observation
- GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
- GRB 240415A: Earliest optical followup with the Kinder observations
- GRB 240414A: GMG observation
- EP240414a: EP-FXT follow-up observation
- GRB 240415B: Swift ToO observations
- GRB 240415A: OHP/T193 optical observations
- GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
- GRB 240415A: SAO RAS optical observations
- GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
- GRB 240414A: Fermi GBM Observation
- Fermi GRB 240415A: Global MASTER-Net observations report
- GRB 240415A: Mondy optical transient detection
- GRB 240414A: Photometric observation from 2.2m CAHA
- IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
- GRB 240414A: Swift/UVOT Detection
- LXT 240402A/GRB 240402B: Swift follow-up observations
- GRB 240414A: Mondy optical observations
- GRB 240414A: AKO Optical Upper Limit
- X-ray transient EP 240414a - GTC spectroscopic observations
- GRB 240415A: Prompt Swift-XRT observations
- GRB 240415A: Swift detection of a burst
- EP240413a: Upper limits from GECAM-B Observation
- EP 240414a: NOT optical counterpart confirmation
- GRB240414A : J-band upper limits from WINTER
- GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
- GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
- LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
- EP240413A: GOTO optical upper limits
- GRB 240414A: Skynet Optical Afterglow Observations
- Swift GRB 240414A: Global MASTER-Net observations report
- EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
- IPN triangulation of GRB 240410A
- EP240413a: possible detection of the X-ray emission with EP-FXT after 14 hours
- IPN triangulation of GRB 240411A
- Fermi-LAT gamma-ray observations of IceCube-240412A
- GRB 240414A : MITSuME Akeno optical upper limits
- GRB 240414A: Redshift confirmation from GTC/OSIRIS+
- GRB 240414A : OHP/T193 redshift determination
- GRB 240414A : OHP/T193 optical counterpart detection
- LIGO/Virgo/KAGRA S240413p: Updated Sky localization
- LIGO/Virgo/KAGRA S240413p: Zwicky Transient Facility observations
- EP240408a: GSP optical upper limit
- GRB 240411B: CrAO/ZTSh optical observations
- GRB 240411B: Kinder observations with Lulin observatory
- LIGO/Virgo/Kagra S240413p: NED Galaxies in the Localization Volume
- LIGO/Virgo/KAGRA S240413p: Identification of a GW compact binary merger candidate
- GRB 240411B: HiPERCAM/GTC observation
- GRB 240411B: Swift-BAT refined analysis
- GRB 240411B: 1.3m DFOT Optical observations
- GRB 240411A: GRBAlpha detection
- GRB 240411B: OHP/T193 optical observations
- GRB 240405A: Glowbug gamma-ray detection
- GRB 240411B: LCO optical afterglow detection
- GRB 240408B: GRBAlpha detection
- EP240408A: MASTER optical observations
- EP240408a: GROND detection of a candidate counterpart
- EP240408a: Swift follow-up observation
- X-ray transient EP240315a: second epoch e-MERLIN radio observations
- GRB 240405A: GRBAlpha detection
- IceCube-240327B: GRANDMA/Kilonova-Catcher observations of 4FGL J0555.9+0030 and optical upper limits
- Fermi GRB 240408A: Global MASTER-Net observations report
- GRB 240402C: CALET Gamma-Ray Burst Monitor detection
- Fermi GRB 240407A: Global MASTER-Net observations report
- Fermi-LAT gamma-ray observations of IceCube-240327B
- Fermi-LAT gamma-ray observations of IceCube-240327A
- LXT 240402A/GRB 240402B: rest-frame energetics from Konus-Wind observation
- Fermi GRB 240405B: Global MASTER-Net observations report
- GRB 240402C: Glowbug gamma-ray detection
- GRB 240331A: GRBAlpha detection
- LXT 240402A/GRB 240402B: GECAM-C refined analysis
- Swift satellite resumes pointed science observations
- GRB 240403A: Glowbug gamma-ray detection
- LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
- X-ray transient LXT 240402A: WFST optical upper limits
- Konus-Wind detection of LXT 240402A/GRB 240402B
- GRB/FXT 240402B: Kinder optical counterpart candidate
- IceCube-240327B: GRANDMA observations of 4FGL J0555.9+0030
- GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
- X-ray transient LXT240402A: AST3-3 optical upper limits
- LXT 240402A: EP-FXT detection of the X-ray afterglow
- Fermi GRB 240404A: Global MASTER-Net observations report
- LXT 240402A: MASTER optical observations with AGN in error-box
- GRB 240402B: GWAC-F50A optical upper limit
- GRB 240402B: GECAM-C detection
- Fermi GRB 240402A: Global MASTER-Net observations report
- X-ray transient EP240331a: Kinder optical upper limits
- X-ray transient EP240331A: GRANDMA-Kilonova catcher optical upper limit
- EP240331A: MASTER optical observations
- Transient EP240315a: J-band observations of AT2024eju with WIRC